Hibiki was born with a chronic heart condition. Because of his health, his daily actions and physical movements are heavily restricted, constantly keeping him from pursuing the active lifestyle and activities he truly wants to experience. One day, he discovers that his classmate, Chiharu, carries the exact same quiet struggle and emotional burden. The story beautifully captures the warm, empathetic bond that forms between two teenagers navigating their limitations through a shared emotional rhythm, subtly mirrored by the steps of a waltz.